U.S. patent number 6,238,754 [Application Number 09/345,756] was granted by the patent office on 2001-05-29 for liquid crystal display device.
This patent grant is currently assigned to Kabushiki Kaisha Toshiba. Invention is credited to Muneharu Akiyoshi, Nobuko Fukuoka, Hitoshi Hatoh, Atsuyuki Manabe, Masumi Manabe, Natsuko Maya, Daisuke Miyazaki, Kisako Ninomiya, Kiyoshi Shohara.
United States Patent |
6,238,754 |
Shohara , et al. |
May 29, 2001 |
Liquid crystal display device
Abstract
Disclosed is a liquid crystal display device, comprising two
substrates each having an alignment film, a sealing member arranged
in the outer peripheries of the two substrates to permit the outer
peripheries of these two substrates, which are arranged such that
the alignment films of these two substrates face each other, to be
bonded to each other except a liquid crystal filling port, a spacer
for keeping the two substrates a predetermined distance apart from
each other, a liquid crystal layer formed by filling a liquid
crystal material through the liquid crystal filling port into the
clearance between the two substrates, and an end-sealing material
for sealing the liquid crystal filling port, wherein total amounts
of an alkyl acid, phenyl carboxylic acid or a phenyl carboxylic
acid derivative, phenylene dicarboxylic acid or a phenylene
dicarboxylic acid derivative, an alkyl amine, aniline or an aniline
derivative, phenylene diamine or a phenylene diamine derivative,
phenyleneamine carboxylic acid or a phenyleneamine carboxylic acid
derivative, an alkyl imide, a phthalimide derivative, a cyano
benzene derivative, and a dicyano benzene derivative contained in
the sealing member, the end-sealing material and the spacer is not
larger than 3%.
Inventors: |
Shohara; Kiyoshi (Urawa,
JP), Miyazaki; Daisuke (Kamakura, JP),
Maya; Natsuko (Fukaya, JP), Akiyoshi; Muneharu
(Urawa, JP), Manabe; Atsuyuki (Fukaya, JP),
Manabe; Masumi (Fukaya, JP), Fukuoka; Nobuko
(Honjyo, JP), Ninomiya; Kisako (Fukaya,
JP), Hatoh; Hitoshi (Yokohama, JP) |
Assignee: |
Kabushiki Kaisha Toshiba
(Kawasaki, JP)
|
Family
ID: |
18179448 |
Appl.
No.: |
09/345,756 |
Filed: |
July 1, 1999 |
Foreign Application Priority Data
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Nov 16, 1998 [JP] |
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10-325673 |
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Current U.S.
Class: |
428/1.5;
252/299.5; 349/153; 349/155; 349/190 |
Current CPC
Class: |
G02F
1/1339 (20130101); C09K 2323/05 (20200801) |
Current International
Class: |
G02F
1/1339 (20060101); G02F 1/13 (20060101); C09K
019/54 (); G02F 001/133 (); G02F 001/133 () |
Field of
Search: |
;428/1.5,1.51 ;252/299.5
;349/190,153,155 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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|
|
|
|
5-127166 |
|
May 1993 |
|
JP |
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5-210095 |
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Aug 1993 |
|
JP |
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9-33912 |
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Feb 1997 |
|
JP |
|
Other References
English abstract of JP 5-127166, 1993.* .
English abstract of JP 9-33912, 1997.* .
English abstract of JP 5-210095, 1997..
|
Primary Examiner: Wu; Shean C.
Attorney, Agent or Firm: Pillsbury Winthrop LLP
Claims
What is claimed is:
1. A liquid crystal display device, comprising two substrates each
having an alignment film, a sealing member arranged in the outer
peripheries of said two substrates to permit the outer peripheries
of these two substrates, which are arranged such that the alignment
films of these two substrates face each other, to be bonded to each
other except a liquid crystal filling port, a spacer for keeping
the two substrates a predetermined distance apart from each other,
a liquid crystal layer formed by filling a liquid crystal material
through said liquid crystal filling port into the clearance between
the two substrates, and an end-sealing material for clogging the
liquid crystal filling port,
wherein total amounts of an alkyl acid represented by formula (1),
phenyl carboxylic acid or a phenyl carboxylic acid derivative
represented by formula (2), phenylene dicarboxylic acid or a
phenylene dicarboxylic acid derivative represented by formula (3),
an alkyl amine represented by formula (4), aniline or an aniline
derivative represented by formula (5), phenylene diamine or a
phenylene diamine derivative represented by formula (6),
phenyleneamine carboxylic acid or a phenyleneamine carboxylic acid
derivative represented by formula (7), an alkyl imide represented
by formula (8), a phthalimide derivative represented by formula
(9), a cyano benzene derivative represented by formula (10), and a
dicyano benzene derivative represented by formula (11) contained in
the sealing member, the end-sealing material and the spacer is not
larger than 3%:
##STR4##
##STR5##
##STR6##
where R.sub.1 is an alkyl group having 1 to 20 carbon atoms,
R.sub.2 is --H or an alkyl group having 1 to 20 carbon atoms,
R.sub.3 is an alkyl group having 1 to 20 carbon atoms, each of V,
W, X, Y and Z is one selected from the group consisting of an alkyl
group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10
carbon atoms, --F, --Cl, --Br, --C.sub.6 H.sub.5 and --H, and n is
1 or 2.
2. A liquid crystal display device, comprising two substrates each
having an alignment film, a sealing member arranged in the outer
peripheries of said two substrates to permit the outer peripheries
of these two substrate, which are arranged such that the alignment
films of these two substrates face each other, to be bonded to each
other except a liquid crystal filling port, a spacer for keeping
the two substrates a predetermined distance apart from each other,
a liquid crystal layer formed by filling a liquid crystal material
through said liquid crystal filling port into the clearance between
the two substrates, and an end-sealing material for sealing the
liquid crystal filling port,
wherein total extraction amounts of an alkyl acid represented by
formula (1), phenyl carboxylic acid or a phenyl carboxylic acid
derivative represented by formula (2), phenylenedicarboxylic acid
or a phenylene dicarboxylic acid derivative represented by formula
(3), an alkyl amine represented by formula (4), aniline or an
aniline derivative represented by formula (5), phenylene diamine or
a phenylene diamine derivative represented by formula (6),
phenyleneamine carboxylic acid or a phenyleneamine carboxylic acid
derivative represented by formula (7), an alkyl imide represented
by formula (8), a phthalimide derivative represented by formula
(9), a cyano benzene derivative represented by formula (10), and a
dicyano benzene derivative represented by formula (11) is not more
than 100 ppm when the sealing member, the end-sealing material and
the spacer are subjected to extraction in the liquid crystal
material:
##STR7##
##STR8##
##STR9##
where R.sub.1 is an alkyl group having 1 to 20 carbon atoms,
R.sub.2 is --H or an alkyl group having 1 to 20 carbon atoms,
R.sub.3 is an alkyl group having 1 to 20 carbon atoms, each of V,
W, X, Y and Z is one selected from the group consisting of an alkyl
group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10
carbon atoms, --F, --Cl, --Br, --C.sub.6 H.sub.5 and --H, and n is
1 or 2.
3. A liquid crystal display device according to claim 1 or 2,
wherein said spacer is formed of a black resin.
4. A liquid crystal display device according to claim 3, wherein
said black resin contains a green pigment.
5. A liquid crystal display device, comprising:
a color filter substrate including a substrate, a colored layer
formed on said substrate, a patterned electrode formed on said
colored layer, and an alignment film formed to cover the colored
layer and said electrode;
a counter substrate arranged to face said color filter
substrate;
a sealing member arranged in the outer peripheries of said color
filter substrate and counter substrate to permit the outer
peripheries of these two substrate to be bonded to each other
except a liquid crystal filling port;
a spacer for keeping the two substrates a predetermined distance
apart from each other;
a liquid crystal layer formed by filling a liquid crystal material
through said liquid crystal filling port into the clearance between
the two substrates; and
an end-sealing material for sealing the liquid crystal filling
port,
wherein total amounts of an alkyl acid represented by formula (1),
phenyl carboxylic acid or a phenyl carboxylic acid derivative
represented by formula (2), phenylene dicarboxylic acid or a
phenylene dicarboxylic acid derivative represented by formula (3),
an alkyl amine represented by formula (4), aniline or an aniline
derivative represented by formula (5), phenylene diamine or a
phenylene diamine derivative represented by formula (6),
phenyleneamine carboxylic acid or a phenyleneamine carboxylic acid
derivative represented by formula (7), an alkyl imide represented
by formula (8), a phthalimide derivative represented by formula
(9), a cyano benzene derivative represented by formula (10), and a
dicyano benzene derivative represented by formula (11) contained in
the colored layer, the sealing member, the end-sealing material and
the spacer is not larger than.3%:
##STR10##
##STR11##
##STR12##
where R.sub.1 is an alkyl group having 1 to 20 carbon atoms,
R.sub.2 is --H or an alkyl group having 1 to 20 carbon atoms,
R.sub.3 is an alkyl group having 1 to 20 carbon atoms, each of V,
W, X, Y and Z is one selected from the group consisting of an alkyl
group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10
carbon atoms, --F, --Cl, --Br, --C.sub.6 H.sub.5 and --H, and n is
1 or 2.
6. A liquid crystal display device, comprising:
a color filter substrate including a substrate, a colored layer
formed on said substrate, a patterned electrode formed on said
colored layer, and an alignment film formed to cover the colored
layer and said electrode;
a counter substrate arranged to face said color filter
substrate;
a sealing member arranged in the outer peripheries of said color
filter substrate and counter substrate to permit the outer
peripheries of these two substrate to be bonded to each other
except a liquid crystal filling port;
a spacer for keeping the two substrates a predetermined distance
apart from each other;
a liquid crystal layer formed by filling a liquid crystal material
through said liquid crystal filling port into the clearance between
the two substrates; and
an end-sealing material for sealing the liquid crystal filling
port,
wherein total extraction amounts of an alkyl acid represented by
formula (1), phenyl carboxylic acid or a phenyl carboxylic acid
derivative represented by formula (2), phenylene dicarboxylic acid
or a phenylene dicarboxylic acid derivative represented by formula
(3), an alkyl amine represented by formula (4), aniline or an
aniline derivative represented by formula (5), phenylene diamine or
a phenylene diamine derivative represented by formula (6),
phenyleneamine carboxylic acid or a phenyleneamine carboxylic acid
derivative represented by formula (7), an alkyl imide represented
by formula (8), a phthalimide derivative represented by formula
(9), a cyano benzene derivative represented by formula (10), and a
dicyano benzene derivative represented by formula (11) is not more
than 100 ppm when the colored layer, the sealing member, the
end-sealing material and the spacer are subjected to extraction in
the liquid crystal material:
##STR13##
##STR14##
##STR15##
where R.sub.1 is an alkyl group having 1 to 20 carbon atoms,
R.sub.2 is --H or an alkyl group having 1 to 20 carbon atoms,
R.sub.3 is an alkyl group having 1 to 20 carbon atoms, each of V,
W, X, Y and Z is one selected from the group consisting of an alkyl
group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10
carbon atoms, --F, --Cl, --Br, --C.sub.6 H.sub.5 and --H, and n is
1 or 2.
7. A liquid crystal display device, comprising:
an array substrate including a plurality of signal lines and a
plurality of scanning lines arranged on one main plane of a
substrate in a manner to cross each other, a switching element
arranged in every cross point between the signal line and the
scanning line, a colored layer arranged to cover at least partially
the signal line, the scanning line and the switching element, and a
plurality of pixel electrodes arranged on the colored layer and
connected to the switching elements through contact holes formed in
the colored layer;
a counter substrate arranged to face said array substrate;
a sealing member arranged in the outer peripheries of said array
substrate and counter substrate to permit the outer peripheries of
these two substrate to be bonded to each other except a liquid
crystal filling port;
a spacer for keeping the two substrates a predetermined distance
apart from each other;
a liquid crystal layer formed by filling a liquid crystal material
through said liquid crystal filling port into the clearance between
the two substrates; and
an end-sealing material for sealing the liquid crystal filling
port,
wherein total amounts of an alkyl acid represented by formula (1),
phenyl carboxylic acid or a phenyl carboxylic acid derivative
represented by formula (2), phenylene dicarboxylic acid or a
phenylene dicarboxylic acid derivative represented by formula (3),
an alkyl amine represented by formula (4), aniline or an aniline
derivative represented by formula (5), phenylene diamine or a
phenylene diamine derivative represented by formula (6),
phenyleneamine carboxylic acid or a phenyleneamine carboxylic acid
derivative represented by formula (7), an alkyl imide represented
by formula (8), a phthalimide derivative represented by formula
(9), a cyano benzene derivative represented by formula (10), and a
dicyano benzene derivative represented by formula (11) contained in
the colored layer, sealing member, the end-sealing material and the
spacer is not larger than 3%:
##STR16##
##STR17##
##STR18##
where R.sub.1 is an alkyl group having 1 to 20 carbon atoms,
R.sub.2 is --H or an alkyl group having 1 to 20 carbon atoms,
R.sub.3 is an alkyl group having 1 to 20 carbon atoms, each of V,
W, X, Y and Z is one selected from the group consisting of an alkyl
group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10
carbon atoms, --F, --Cl, --Br, --C.sub.6 H.sub.5 and --H, and n is
1 or 2.
8. A liquid crystal display device, comprising:
an array substrate including a plurality of signal lines and a
plurality of scanning lines arranged on one principle plane of a
substrate in a manner to cross each other, a switching element
arranged in every cross point between the signal line and the
scanning line, a colored layer arranged to cover at least partially
the signal line, the scanning line and the switching element, and a
plurality of pixel electrodes arranged on the colored layer and
connected to the switching elements through contact holes formed in
the colored layer;
a counter substrate arranged to face said array substrate;
a sealing member arranged in the outer peripheries of said array
substrate and counter substrate to permit the outer peripheries of
these two substrate to be bonded to each other except a liquid
crystal filling port;
a spacer for keeping the two substrates a predetermined distance
apart from each other;
a liquid crystal layer formed by filling a liquid crystal material
through said liquid crystal filling port into the clearance between
the two substrates; and
an end-sealing material for sealing the liquid crystal filling
port,
wherein total extraction amounts of an alkyl acid represented by
formula (1), phenyl carboxylic acid or a phenyl carboxylic acid
derivative represented by formula (2), phenylene dicarboxylic acid
or a phenylene dicarboxylic acid derivative represented by formula
(3), an alkyl amine represented by formula (4), aniline or an
aniline derivative represented by formula (5), phenylene diamine or
a phenylene diamine derivative represented by formula (6),
phenyleneamine carboxylic acid or a phenyleneamine carboxylic acid
derivative represented by formula (7), an alkyl imide represented
by formula (8), a phthalimide derivative represented by formula
(9), a cyano benzene derivative represented by formula (10), and a
dicyano benzene derivative represented by formula (11) is not more
than 100 ppm when the colored layer, sealing member, the
end-sealing material and the spacer are subjected to extraction in
the liquid crystal material:
##STR19##
##STR20##
##STR21##
where R.sub.1 is an alkyl group having 1 to 20 carbon atoms,
R.sub.2 is --H or an alkyl group having 1 to 20 carbon atoms,
R.sub.3 is an alkyl group having 1 to 20 carbon atoms, each of V,
W, X, Y and Z is one selected from the group consisting of an alkyl
group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10
carbon atoms, --F, --Cl, --Br, --C.sub.6 H.sub.5 and --H, and n is
1 or 2.
9. A liquid crystal display device according to any one of claims 5
to 8, wherein said colored layer consists of resin layers of red,
blue and green.
10. A liquid crystal display device according to claim 9, wherein
said spacer consists of a black resin layer.
11. A liquid crystal display device according to claim 9, wherein
said black resin contains a green pigment.
12. A liquid crystal display device, comprising an array substrate
and a counter substrate arranged to face each other, a liquid
crystal layer arranged between said array substrate and said
counter substrate, and a colored layer arranged on one of the array
substrate and the counter substrate,
wherein total amounts of an alkyl acid represented by formula (1),
phenyl carboxylic acid or a phenyl carboxylic acid derivative
represented by formula (2), phenylene dicarboxylic acid or a
phenylene dicarboxylic acid derivative represented by formula (3),
an alkyl amine represented by formula (4), aniline or an aniline
derivative represented by formula (5), phenylene diamine or a
phenylene diamine derivative represented by formula (6),
phenyleneamine carboxylic acid or a phenyleneamine carboxylic acid
derivative represented by formula (7), an alkyl imide represented
by formula (8), a phthalimide derivative represented by formula
(9), a cyano benzene derivative represented by formula (10), and a
dicyano benzene derivative represented by formula (11) contained in
the colored layer is not larger than 3%:
##STR22##
##STR23##
##STR24##
where R.sub.1 is an alkyl group having 1 to 20 carbon atoms,
R.sub.2 is --H or an alkyl group having 1 to 20 carbon atoms,
R.sub.3 is an alkyl group having 1 to 20 carbon atoms, each of V,
W, X, Y and Z is one selected from the group consisting of an alkyl
group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10
carbon atoms, --F, --Cl, --Br, --C.sub.6 H.sub.5 and --H, and n is
1 or 2.
13. A liquid crystal display device, comprising an array substrate
and a counter substrate arranged to face each other, a liquid
crystal layer arranged between said array substrate and said
counter substrate, and a colored layer arranged on one of the array
substrate and the counter substrate,
wherein total extraction amounts of an alkyl acid represented by
formula (1), phenyl carboxylic acid or a phenyl carboxylic acid
derivative represented by formula (2), phenylene dicarboxylic acid
or a phenylene dicarboxylic acid derivative represented by formula
(3), an alkyl amine represented by formula (4), aniline or an
aniline derivative represented by formula (5), phenylene diamine or
a phenylene diamine derivative represented by formula (6),
phenyleneamine carboxylic acid or a phenyleneamine carboxylic acid
derivative represented by formula (7), an alkyl imide represented
by formula (8), a phthalimide derivative represented by formula
(9), a cyano benzene derivative represented by formula (10), and a
dicyano benzene derivative represented by formula (11) is not more
than 100 ppm when the colored layer is subjected to in the liquid
crystal material:
##STR25##
##STR26##
##STR27##
where R.sub.1 is an alkyl group having 1 to 20 carbon atoms,
R.sub.2 is --H or an alkyl group having 1 to 20 carbon atoms,
R.sub.3 is an alkyl group having 1 to 20 carbon atoms, each of V,
W, X, Y and Z is one selected from the group consisting of an alkyl
group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10
carbon atoms, --F, --Cl, --Br, --C.sub.6 H.sub.5 and --H, and n is
1 or 2.
14. A liquid crystal display device, comprising:
a substrate;
a colored layer arranged on said substrate and consisting of resins
colored red, blue and green;
a patterned electrode arranged on the colored layer;
a color filter substrate including said colored layer and an
alignment film formed to cover said electrode;
a counter substrate arranged to face said color filter
substrate;
a sealing member arranged in the outer peripheries of said color
filter substrate and counter substrate to permit the outer
peripheries of these two substrates to be bonded to each other
except a liquid crystal filling port;
a spacer for keeping the two substrates a predetermined distance
apart from each other;
a liquid crystal layer formed by filling a liquid crystal material
through said liquid crystal filling port into the clearance between
the two substrates; and
an end-sealing material for sealing the liquid crystal filling
port,
wherein total amount of an alkyl acid represented by formula (1),
phenyl carboxylic acid or a phenyl carboxylic acid derivative
represented by formula (2), phenylene dicarboxylic acid or a
phenylene dicarboxylic acid derivative represented by formula (3),
an alkyl amine represented by formula (4), aniline or an aniline
derivative represented by formula (5), phenylene diamine or a
phenylene diamine derivative represented by formula (6),
phenyleneamine carboxylic acid or a phenyleneamine carboxylic acid
derivative represented by formula (7), an alkyl imide represented
by formula (8), a phthalimide derivative represented by formula
(9), a cyano benzene derivative represented by formula (10), and a
dicyano benzene derivative represented by formula (11) contained in
the green resin used in the colored layer is not larger than 3%
after formation of the colored layer:
##STR28##
##STR29##
##STR30##
where R.sub.1 is an alkyl group having 1 to 20 carbon atoms,
R.sub.2 is --H or an alkyl group having 1 to 20 carbon atoms,
R.sub.3 is an alkyl group having 1 to 20 carbon atoms, each of V,
W, X, Y and Z is one selected from the group consisting of an alkyl
group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10
carbon atoms, --F, --Cl, --Br, --C.sub.6 H.sub.5 and --H, and n is
1 or 2.
15. A liquid crystal display device, comprising:
a substrate;
a colored layer arranged on said substrate and consisting of resins
colored red, blue and green;
a patterned electrode arranged on the colored layer;
a color filter substrate including said colored layer and an
alignment film formed to cover said electrode;
a counter substrate arranged to face said color filter
substrate;
a sealing member arranged in the outer peripheries of said color
filter substrate and counter substrate to permit the outer
peripheries of these two substrates to be bonded to each other
except a liquid crystal filling port;
a spacer, which consists essentially of a black resin, for keeping
the two substrates a predetermined distance apart from each
other;
a liquid crystal layer formed by filling a liquid crystal material
through said liquid crystal filling port into the clearance between
the two substrates; and
an end-sealing material for sealing the liquid crystal filling
port,
wherein total amounts of an alkyl acid represented by formula (1),
phenyl carboxylic acid or a phenyl carboxylic acid derivative
represented by formula (2), phenylene dicarboxylic acid or a
phenylene dicarboxylic acid derivative represented by formula (3),
an alkyl amine represented by formula (4), aniline or an aniline
derivative represented by formula (5), phenylene diamine or a
phenylene diamine derivative represented by formula (6),
phenyleneamine carboxylic acid or a phenyleneamine carboxylic acid
derivative represented by formula (7), an alkyl imide represented
by formula (8), a phthalimide derivative represented by formula
(9), a cyano benzene derivative represented by formula (10), and a
dicyano benzene derivative represented by formula (11) contained in
said black resin and the green resin used in the colored layer is
not larger than 3% after formation of the colored layer:
##STR31##
##STR32##
##STR33##
where R.sub.1 is an alkyl group having 1 to 20 carbon atoms,
R.sub.2 is --H or an alkyl group having 1 to 20 carbon atoms,
R.sub.3 is an alkyl group having 1 to 20 carbon atoms, each of V,
W, X, Y and Z is one selected from the group consisting of an alkyl
group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10
carbon atoms, --F, --Cl, --Br, --C.sub.6 H.sub.5 and --H, and n is
1 or 2.
16. A liquid crystal display device, comprising:
an array substrate including a plurality of signal lines and a
plurality of scanning lines arranged on one main plane of a
substrate in a manner to cross each other, a switching element
arranged in every cross point between the signal line and the
scanning line, a colored layer consisting of red, blue and green
resins and arranged to cover at least partially the signal line,
the scanning line and the switching element, and a plurality of
pixel electrodes arranged on the colored layer and connected to the
switching elements through contact holes formed in the colored
layer;
a counter substrate arranged to face said array substrate;
a sealing member arranged in the outer peripheries of said array
substrate and counter substrate to permit the outer peripheries of
these two substrates to be bonded to each other except a liquid
crystal filling port;
a spacer, which consists essentially of a black resin, for keeping
the two substrates a predetermined distance apart from each
other;
a liquid crystal layer formed by filling a liquid crystal material
through said liquid crystal filling port into the clearance between
the two substrates; and
an end-sealing material for sealing the liquid crystal filling
port,
wherein total amounts of an alkyl acid represented by formula (1),
phenyl carboxylic acid or a phenyl carboxylic acid derivative
represented by formula (2), phenylene dicarboxylic acid or a
phenylene dicarboxylic acid derivative represented by formula (3),
an alkyl amine represented by formula (4), aniline or an aniline
derivative represented by formula (5), phenylene diamine or a
phenylene diamine derivative represented by formula (6),
phenyleneamine carboxylic acid or a phenyleneamine carboxylic acid
derivative represented by formula (7), an alkyl imide represented
by formula (8), a phthalimide derivative represented by formula
(9), a cyano benzene derivative represented by formula (10), and a
dicyano benzene derivative represented by formula (11) contained in
said black resin and the green resin used in the colored layer is
not larger than 3% after formation of the colored layer:
##STR34##
##STR35##
##STR36##
where R.sub.1 is an alkyl group having 1 to 20 carbon atoms,
R.sub.2 is --H or an alkyl group having 1 to 20 carbon atoms,
R.sub.3 is an alkyl group having 1 to 20 carbon atoms, each of V,
W, X, Y and Z is one selected from the group consisting of an alkyl
group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10
carbon atoms, --F, --Cl, --Br, --C.sub.6 H.sub.5 and --H, and n is
1 or 2.
17. A liquid crystal display device, comprising:
an array substrate including a plurality of signal lines and a
plurality of scanning lines arranged on one main plane of a
substrate in a manner to cross each other, a switching element
arranged in every cross point between the signal line and the
scanning line, a colored layer consisting essentially of red, blue
and green resins and arranged to cover at least partially the
signal line, the scanning line and the switching element, and a
plurality of pixel electrodes arranged on the colored layer and
connected to the switching elements through contact holes formed in
the colored layer;
a counter substrate arranged to face said array substrate;
a sealing member arranged in the outer peripheries of said array
substrate and counter substrate to permit the outer peripheries of
these two substrates to be bonded to each other except a liquid
crystal filling port;
a spacer, which consists essentially of a black resin, for keeping
the two substrates a predetermined distance apart from each
other;
a liquid crystal layer formed by filling a liquid crystal material
through said liquid crystal filling port into the clearance between
the two substrates; and
an end-sealing material for sealing the liquid crystal filling
port,
wherein total extraction amounts of an alkyl acid represented by
formula (1), phenyl carboxylic acid or a phenyl carboxylic acid
derivative represented by formula (2), phenylene dicarboxylic acid
or a phenylene dicarboxylic acid derivative represented by formula
(3), an alkyl amine represented by formula (4), aniline or an
aniline derivative represented by formula (5), phenylene diamine or
a phenylene diamine derivative represented by formula (6),
phenyleneamine carboxylic acid or a phenyleneamine carboxylic acid
derivative represented by formula (7), an alkyl imide represented
by formula (8), a phthalimide derivative represented by formula
(9), a cyano benzene derivative represented by formula (10), and a
dicyano benzene derivative represented by formula (11) is not more
than 100 ppm when the black resin and the green resin used in the
colored layer are subjected to extraction in the liquid crystal
material:
##STR37##
##STR38##
##STR39##
where R.sub.1 is an alkyl group having 1 to 20 carbon atoms,
R.sub.2 is --H or an alkyl group having 1 to 20 carbon atoms,
R.sub.3 is an alkyl group having 1 to 20 carbon atoms, each of V,
W, X, Y and Z is one selected from the group consisting of an alkyl
group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10
carbon atoms, --F, --Cl, --Br, --C.sub.6 H.sub.5 and --H, and n is
1 or 2.
18. A colored layer material for a liquid crystal display device,
said colored layer material consisting essentially of resin
containing a green pigment,
wherein total amounts of an alkyl acid represented by formula (1),
phenyl carboxylic acid or a phenyl carboxylic acid derivative
represented by formula (2), phenylene dicarboxylic acid or a
phenylene dicarboxylic acid derivative represented by formula (3),
an alkyl amine represented by formula (4), aniline organ aniline
derivative represented by formula (5), phenylene diamine or a
phenylene diamine derivative represented by formula (6),
phenyleneamine carboxylic acid or a phenyleneamine carboxylic acid
derivative represented by formula (7), an alkyl imide represented
by formula (8), a phthalimide derivative represented by formula
(9), a cyano benzene derivative represented by formula (10), and a
dicyano benzene derivative represented by formula (11) is not
larger than 3% when said colored layer material is cured:
##STR40##
##STR41##
##STR42##
where R.sub.1 is an alkyl group having 1 to 20 carbon atoms,
R.sub.2 is --H or an alkyl group having 1 to 20 carbon atoms,
R.sub.3 is an alkyl group having 1 to 20 carbon atoms, each of V,
W, X, Y and Z is one selected from the group consisting of an alkyl
group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10
carbon atoms, --F, --Cl, --Br, --C.sub.6 H.sub.5 and --H, and n is
1 or 2.
19. A colored layer material for a liquid crystal display device,
said colored layer material consisting essentially of resin
containing a green pigment,
wherein total extraction amounts of an alkyl acid represented by
formula (1), phenyl carboxylic acid or a phenyl carboxylic acid
derivative represented by formula (2), phenylene dicarboxylic acid
or a phenylene dicarboxylic acid derivative represented by formula
(3), an alkyl amine represented by formula (4), aniline or an
aniline derivative represented by formula (5), phenylene diamine or
a phenylene diamine derivative represented by formula (6),
phenyleneamine carboxylic acid or a phenyleneamine carboxylic acid
derivative represented by formula (7), an alkyl imide represented
by formula (8), a phthalimide derivative represented by formula
(9), a cyano benzene derivative represented by formula (10), and a
dicyano benzene derivative represented by formula (11) is not more
than 100 ppm when the colored layer material is cured and, then,
subjected to extraction in the liquid crystal material:
##STR43##
##STR44##
##STR45##
where R.sub.1 is an alkyl group having 1 to 20 carbon atoms,
R.sub.2 is --H or an alkyl group having 1 to 20 carbon atoms,
R.sub.3 is an alkyl group having 1 to 20 carbon atoms, each of V,
W, X, Y and Z is one selected from the group consisting of an alkyl
group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10
carbon atoms, --F, --Cl, --Br, --C.sub.6 H.sub.5 and --H, and n is
1 or 2.
Description
BACKGROUND OF THE INVENTION
The present invention relates to a liquid crystal display device, a
color filter substrate used therein and a color filter member.
A liquid crystal display device comprises two electrode substrates
each having an alignment film and arranged such that the alignment
films of the two substrates face each other and a liquid crystal
layer arranged between the two substrates. The two electrode
substrates are bonded to each other with a sealing member arranged
in the peripheral region of the substrate and an end-sealing
material. Also, a granular spacer or a spacer column made of a
resin and formed by a photolithography method is arranged between
the two substrates for keeping these two substrates a predetermined
distance apart from each other. For allowing the liquid crystal
display device to perform a color display, colored layers of red
(R), green (G) and blue (B) are arranged on one of the substrates
and, as desired, a transparent protective layer made of a resin is
formed on the substrate having colored layers and a switching
element mounted thereto.
In a liquid crystal display device of the particular construction,
nonuniformity such as an image sticking and a display unevenness
taking place after the durability (reliability) test are derived
from the members in direct contact with the liquid crystal layer or
the alignment film such as the sealing member, the end-sealing
material, the spacer material, the protective layer and the colored
layer.
BRIEF SUMMARY OF THE INVENTION
An object of the present invention is to provide a liquid crystal
display device that permits preventing the display unevenness, etc.
derived from the members in direct contact with the liquid crystal
layer or the alignment film.
Another object is to provide a member of a colored layer of a
liquid crystal display device that permits preventing the display
unevenness, etc. derived from the members in direct contact with
the liquid crystal layer or the alignment film.
In the present invention, total amounts of an alkyl acid, phenyl
carboxylic acid, a phenyl carboxylic acid derivative, phenylene
dicarboxylic acid, a phenylene dicarboxylic acid derivative, an
alkyl amine, aniline, an aniline derivative, phenylene diamine, a
phenylene diamine derivative, phenyleneamine carboxylic acid, a
phenyleneamine carboxylic acid derivative and an alkyl imide
contained in or extracted from the sealing member, the end-sealing
material, the spacer, the colored layer, etc. is controlled to fall
within a predetermined range so as to prevent alignment unevenness
and image sticking.
The alignment unevenness or image sticking is considered to take
place by eluation into the liquid crystal or adsorption on the
alignment film of organic impurities contained in the sealing
member, the end-sealing material, the spacer material, the colored
layer, etc. such as an alkyl acid, phenyl carboxylic acid, a phenyl
carboxylic acid derivative, phenylene dicarboxylic acid, a
phenylene dicarboxylic acid derivative, an alkyl amine, aniline, an
aniline derivative, phenylene diamine, a phenylene diamine
derivative, phenyleneamine carboxylic acid, a phenyleneamine
carboxylic derivatives an alkyl imide, a phthalimide derivative, a
cyano benzene derivative, and a dicyano benzene derivative, when
the liquid crystal layer is held between the electrode substrates
to assemble a liquid crystal display device. In other words, the
alignment unevenness or image sticking is considered to take place
in the case where the sealing member, the end-sealing material, the
spacer material, the colored layer, etc. include a region that is
brought into direct contact with the liquid crystal layer or the
alignment film. It is considered reasonable to understand that the
impurities contained in the sealing member, the end-sealing
material, the spacer material, the colored layer, etc. permeate
into the liquid crystal layer or the alignment film that are
included in the display region so as to bring about eluation of
these impurities into the liquid crystal layer and adsorption of
these impurities on the alignment film so as to generate the
alignment unevenness and image sticking. These impurities have been
found to be contained in large amounts in, particularly, the green
layer and the black layer included in the colored layers. Pigments
G7 and G36 are generally used as parts of the green coloring
material and the black coloring material of the color filter
included in the liquid crystal display device. The impurities given
above are contained in large amounts in these pigments. Further,
impurities are contained in large amounts in the dispersant and
polymer components used for dispersing these pigments into a
colored paste. It is also conceivable that impurities are mixed
unexpectedly in the resist preparation step in which the colored
paste is mixed and dispersed. Further, the pigments and the
dispersant are considered to be decomposed under high temperatures,
by contact with an alkali or by exposure to an ultraviolet light,
so as to generate the organic impurities noted above. Therefore,
the green layer has been found to cause large amounts of impurities
to be generated in the liquid crystal layer and the alignment film,
compared with the red or blue layer. It is possible to suppress
generation of the organic impurities by suitably refining the
pigment and dispersant for preparation of a resist used for forming
the green layer and by suitably selecting the materials used for
the refining.
The present inventors have conducted a simple evaluation test in
respect of the influences (particularly, image sticking) given to
the display when various organic and inorganic substances are
contained in a liquid crystal cell and when the materials used are
refined. The experiment was conducted as follows.
Specifically, a TN liquid crystal cell was prepared by coating an
alignment film on each of an array substrate having a switching
element and a pixel electrode formed on a glass substrate and a
counter substrate having a counter electrode formed on a glass
substrate, followed by arranging these two substrates to permit the
alignment films to face each other with a liquid crystal layer
interposed therebetween. Two kinds of alignment film materials and
two kinds of liquid crystal materials were used in the experiment,
and the image sticking and display unevenness taking place after a
durability (reliability) test were evaluated under the conditions
that various organic and inorganic substances were attached to the
alignment films. Table 1 shows the results.
TABLE 1 Display characteristics Liquid crystal A Liquid crystal B
nonuniform image nonuniform image sticking/nonuniform
sticking/nonuniform Alignment reliability (display reliability
(display Attached substance film unevenness) unevenness) 1 phthalic
acid P1 x/x x/x 2 phthalic acid P2 x/x x/x 3 terephthalic acid P1
x/x x/x 4 terephthalic acid P2 x/x .DELTA./x 5 para-phthalic acid
P1 x/x x/x 6 para-phthalic acid P2 .DELTA./x .DELTA./.DELTA. 7
dichlorophthalic acid P1 x/x x/x 8 dichlorophthalic acid P2 x/x
.DELTA./x 9 benzoic acid P1 x/x .DELTA./x 10 benzoic acid P2 x/x
.DELTA./.DELTA. 11 decanoic acid P1 x/x x/x 12 decanoic acid P2 x/x
.DELTA./x 13 tetradecanoic acid P1 x/x x/x 14 tetradecanoic acid P2
x/x .DELTA./x 15 acetic acid P1 x/x .DELTA./x 16 acetic acid P2
.DELTA./x .DELTA./.DELTA. 17 oxalic acid P1 x/x x/x 18 oxalic acid
P2 .DELTA./.DELTA. .DELTA./.DELTA. 19 hexadecamine P1 x/x
.DELTA./.DELTA. 20 hexadecamine P2 x/x .DELTA./.DELTA. 21 aniline
P1 x/x .DELTA./.DELTA. 22 aniline P2 .DELTA./x .DELTA./.DELTA. 23
N-methyl aniline P1 x/x .DELTA./x 24 N-methyl aniline P2 x/x
.DELTA./.DELTA. 25 phthalic acid amide P1 x/x x/x 26 phthalic acid
amide P2 .DELTA./.DELTA. .DELTA./.DELTA. 27 N-methylamino aniline
P1 x/x x/x 28 N-methylamino aniline P2 x/x .DELTA./.DELTA. 29
para-chlorobenzoic acid P1 x/x .DELTA./.DELTA. 30
para-chlorobenzoic acid P2 .DELTA./x .DELTA./.DELTA. 31 table salt
P1 .largecircle./.largecircle. .largecircle./.largecircle. 32
hydrochloric acid P2 .largecircle./.largecircle.
.largecircle./.largecircle. 33 calcium carbonate P1
.largecircle./.largecircle. .largecircle./.largecircle. 34 phthalic
anhydride P2 .largecircle./.largecircle.
.largecircle./.largecircle. 35 hexadecane P1
.largecircle./.largecircle. .largecircle./.largecircle. 36 toluene
P1 .largecircle./.largecircle. .largecircle./.largecircle. 37
ethanol P1 .largecircle./.largecircle. .largecircle./.largecircle.
Notes: Alignment film: P1 . . . SE-5291 (trade name); P2 . . .
Al-1051 (trade name) Liquid Crystal: A . . . ZLI-1565 (trade name);
B . . . LIXON-5 (trade name) x . . . occurrence of nonuniform image
sticking/nonuniform reliability (display unevenness) .DELTA. . . .
occurrence of slightly nonuniform image sticking/slightly
nonuniform reliability (display unevenness) .largecircle. . . . no
occurrence of nonuniform image sticking/nonuniform reliability
(display unevenness)
A soluble polyimide SE-5291 manufactured by Nissan Chemical K. K.
and a soluble polyimide A1-1051 manufactured by JSR K. K. were used
for forming alignment films P1 and P2, respectively, shown in Table
1. Also, cyano series liquid crystal material ZLI-1565 manufactured
by E. Merc Inc. and LIXON5001 manufactured by Chisso K. K. were
used as liquid crystals A and B, respectively, shown in Table 1.
For preparing the liquid crystal cell, an array substrate and a
counter substrate were prepared first. Then, each of these
substrates was coated with an alignment film material, followed by
applying a heat treatment to the coating at 180.degree. C. for 60
minutes and subsequently applying a rubbing treatment to the
coating to prepare an alignment film. The alignment film thus
prepared was partially coated with 1 .mu.liter of an IPA (isopropyl
alcohol) solution prepared by dissolving 10% by weight of the
organic or inorganic substance shown in Table 1 as an attached
material in IPA, followed by arranging the array substrate and the
counter substrate to face each other with a liquid crystal layer
interposed therebetween so as to assemble the liquid crystal cell.
For evaluating the nonuniform image sticking, a checker pattern of
the liquid crystal cell was kept imaged for 3 hours for evaluating
the degree of nonuniform image sticking of the checker pattern in
the vicinity of the coated region by the whole tone display
pattern. Further, the liquid crystal cell was kept imaged for 100
hours at 50.degree. C. and a relative humidity of 80% for
evaluating the display unevenness, by a reliability test. Through
these evaluation tests, the present inventors have found that the
presence of specified organic substances within the liquid crystal
cell brings about an image sticking and a display unevenness in the
reliability test, as shown in Table 1. The specified organic
substances noted above include an alkyl acid represented by formula
(1), phenyl carboxylic acid or a phenyl carboxylic acid derivative
represented by formula (2), phenylene dicarboxylic acid or a
phenylene dicarboxylic acid derivative represented by formula (3),
an alkyl amine represented by formula (4), aniline or an aniline
derivative represented by formula (5), phenylene diamine or a
phenylene diamine derivative represented by formula (6),
phenyleneamine carboxylic acid or a phenyleneamine carboxylic acid
derivative represented by formula (7), an alkyl imide represented
by formula (8), a phthalimide derivative represented by formula
(9), a cyano benzene derivative represented by formula (10), and a
dicyano benzene derivative represented by formula (11):
##STR1##
##STR2##
##STR3##
where R.sub.1 is an alkyl group having 1 to 20 carbon atoms,
R.sub.2 is --H or an alkyl group having 1 to 20 carbon atoms,
R.sub.3 is an alkyl group having 1 to 20 carbon atoms, each of V,
W, X, Y and Z is one selected from the group consisting of an alkyl
group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10
carbon atoms, --F, --Cl, --Br, --C.sub.6 H.sub.5 and --H, and n is
1 or 2.
In the present invention, the impurity content represents the
percentage by weight (% by weight) based on the total amount of the
sealing member, the end-sealing material, the spacer material and
the colored layer of the liquid crystal cell, i.e., the impurity
content under the condition that these cell members of the liquid
crystal cell were cured. On the other hand, the extraction amount
represents a value when the cell members were assembled to form a
liquid crystal cell, i.e., a value when the sealing member, the
end-sealing material, the spacer material and the colored layer
after curing were extracted into the liquid crystal. For
extraction, the cured pieces of the cell members and the liquid
crystal were put in an ampule tube and, after the ampule tube was
sealed, stored for 100 hours at 80.degree. C. for the analysis. The
amounts of the cured pieces of the cell members were found to be 10
mm.sup.3 for the colored layer, 2 mm.sup.3 for the sealing member,
0.1 mm.sup.3 for the spacer material, and 0.05 mm.sup.3 for the
end-sealing material. The amount of the liquid crystal was 50 cc. A
fluorine-contained liquid crystal and a cyano-contained nematic
liquid crystal can be used as a liquid crystal material for the
extraction. Specifically, used were a cyano-contained liquid
crystal of ZLI-1565 manufactured by E. Merc Inc. and a
fluorine-contained liquid crystal of LOXON50001 manufactured by
Chisso K. K. It is possible to use "Shimazu 14A" (trade name of a
gas chromatography analytical apparatus manufactured by Shimazu
Seisakusho K. K.) or "Shimazu 10AS" (trade name of a liquid
chromatography analytical apparatus manufactured by Shimazu
Seisakusho K. K.) as a measuring apparatus. A gas chromatography
analytical apparatus was used this time.
Additional objects and advantages of the invention will be set
forth in the description which follows, and in part will be obvious
from the description, or may be learned by practice of the
invention. The objects and advantages of the invention may be
realized and obtained by means of the instrumentalities and
combinations particularly pointed out hereinafter.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
The accompanying drawings, which are incorporated in and constitute
a part of the specification, illustrate presently preferred
embodiments of the invention, and together with the general
description given above and the detailed description of the
preferred embodiments given below, serve to explain the principles
of the invention.
FIG. 1 is a vertical cross sectional view showing a liquid crystal
display device according to one embodiment of the present
invention;
FIG. 2 is a vertical cross sectional view showing an array
substrate included in the liquid crystal display device according
to the embodiment of the present invention;
FIG. 3 is a vertical cross sectional view showing a liquid crystal
display device according to another embodiment of the present
invention; and
FIG. 4 is a plan view schematically showing the coating positions
of the sealing member and the end-sealing material included in the
liquid crystal display device of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
A liquid crystal display device according to a first embodiment of
the present invention will now be described with reference to FIGS.
1 and 2.
FIG. 1 schematically shows a liquid crystal display device of the
present invention and schematically illustrates the color filter
substrate included in the liquid crystal display device shown in
FIG. 2.
As shown in FIG. 1, a liquid crystal display device 10 includes a
counter substrate 120, a color filter substrate 110, and a liquid
crystal layer 70 held between the substrates 120 and 110. These two
substrates are held apart from each other by, for example, a
granular spacer 31. As shown in FIG. 4, the counter substrate 120
and the color filter substrate 110 are bonded to each other by a
sealing member 25 arranged to surround the outer peripheries of
these substrates except a liquid crystal filling port 32. Also, the
liquid crystal filling port 32 is sealed with an end-sealing
material 33. ZLI-1565 manufactured by E. Merc Inc. was used as the
liquid crystal material. Also, a thermosetting epoxy series
adhesive ES-5500 manufactured by Mitsui Toatsu Kagaku K. K. was
used as the sealing material.
The counter substrate 120 includes a transparent substrate 21, a
transparent electrode 22 made of ITO and formed on the substrate
21, and an alignment film 13 formed on the electrode 22.
As shown in FIG. 2, the array substrate includes a transparent
substrate 11. A scanning line (not shown) made of MoW
(molybdenum.multidot.tungsten) and a gate electrode 16 are formed
on the transparent substrate 11. A gate insulating film 12 made of
silicon oxide or silicon nitride is arranged to cover the scanning
line and the gate electrode 16. A semiconductor layer 15 made of
amorphous silicon or the like is formed on the gate insulating film
12. Further, a source electrode 20, a drain electrode 18 and a
signal line (not shown) each having a three-layer structure of
Mo/Al/Mo are also formed on the gate insulating film 12. The signal
line and the scanning line are arranged to cross each other. A
switching element 14 consisting of the gate electrode 16, the gate
insulating film 12, the semiconductor layer 15, the source
electrode 20 and the drain electrode 18 and a pixel electrode 30
connected to the switching element 14 are arranged at each cross
point between the signal line and the scanning line. Further, a red
(R) colored layer 24a, a green (G) colored layer 24b and a blue (B)
colored layer 24c are arranged to cover the switching element 14
and to form a stripe on the entire substrate surface. The pixel
electrode 30, which is positioned on the colored layer 24, is
connected to the source electrode 20 via a contact hole 26 formed
in the colored layer 24. Further, an alignment film 13 is formed on
the entire substrate surface to cover the pixel electrode 30 and
the colored layer 24. The colored layer portions were formed of
CG-2000, CR-2000 and CB-2000 (trade names of ultraviolet light
curing type acrylic resins manufactured by Fuji Hunt Technology K.
K.) and the alignment film was formed of AL-1051 (trade name of
polyimide manufactured by JSR K. K.).
The manufacturing process of the liquid crystal display device of
this embodiment and the relationship between the amount of the
impurities contained in the colored layer and the display
characteristics will now be described.
The manufacturing process of the color filter substrate 110 will be
described first. In the first step, the gate electrode 16 and the
scanning line were formed by depositing a
molybdenum.multidot.tungsten film in a thickness of about 0.3 .mu.m
by a sputtering method on the transparent substrate 11, followed by
pattering the deposited film. Then, an amorphous silicon film was
deposited by a CVD method, followed by patterning the deposited
film to form the semiconductor layer 15 of TFT. Further, Mo, Al and
Mo were deposited successively, followed by patterning the
deposited films to form the signal line, the source electrode 20
and the drain electrode 18.
In the next step, the substrate surface having the electrodes
formed thereon was coated with an ultraviolet light curing type
acrylic red resist solution CR-2000 by a spin coating method. The
coating was pre-baked for about 5 minutes at about 90.degree. C.,
followed by exposing the pre-baked coating to an ultraviolet light
having an intensity of 150 mJ/cm.sup.2 through a predetermined mask
pattern. The photo mask pattern used in this step included a stripe
pattern corresponding to the red colored layer and a circular
pattern having a diameter of 15 .mu.m corresponding to the contact
hole 26 for connecting the pixel electrode 30 to the source
electrode 20. Then, development was performed for about 60 minutes
by using an aqueous solution containing about 0.1% by weight of
TMAH (tetramethylammonium hydride), followed by water wash and,
then, post-baking for about one hour at about 200.degree. C. so as
to form the red colored layer 24a including the contact hole
26.
Then, the green colored layer 24b and the blue colored layer 24c
were formed similarly.
Further, indium tin oxide (ITO) was deposited on the colored layer
24 by a sputtering method, followed by patterning the resultant ITO
layer to form the pixel electrode 30. Then, the entire surface of
the substrate was coated with polyimide used as a material of the
alignment film, followed by applying an alignment treatment to the
polyimide coating to form the alignment film so as to obtain the
color filter substrate 110.
In the next step, ITO was deposited in a thickness of about 100 nm
by a sputtering method on the transparent substrate 21 to prepare
the counter electrode 22. Then, the entire surface of the substrate
was coated with polyimide used as a material of the alignment film,
followed by applying an alignment treatment to the polyimide
coating to form the alignment film so as to prepare the counter
substrate 120.
Granular spacer particles 31 each having a diameter of about 5
.mu.m were dispersed on the alignment film of the counter substrate
120 at a rate of about 100 particles per square millimeter. Then,
the outer peripheral portion of the counter substrate 120 was
coated with the sealing member 25 having fibers of a predetermined
size mixed therein except the liquid crystal filling port. The
counter substrate 120 of the particular condition was bonded to the
color filter substrate 110 using the sealing member 25 so as to
form a vacant cell.
Finally, a nematic liquid crystal material having a chiral material
added thereto was introduced under vacuum into the cell through the
liquid crystal filling port. After the filling, the filling port
was sealed with an ultraviolet light curing resin used as the
end-sealing material 33, followed by arranging polarizing plates on
both sides of the cell so as to form the liquid crystal display
device.
The present inventors have found through the trial manufacture that
the impurities contained in the sealing material, the end-sealing
material, the spacer material and the colored layer are eluded into
the liquid crystal or adsorbed on the alignment film so as to bring
about the display unevenness and nonuniform image sticking and that
the display unevenness and the nonuniform image sticking can be
prevented by regulating the impurity content. The specific
impurities were already described herein under the heading "Brief
Summary of the Invention".
Tables 2 to 5 show experimental data covering the cases where
various impurities were added to the liquid crystal cell included
in the liquid crystal display device described above. The total
impurity content shown in the Tables denotes the percentage by
weight of the impurities based on the sum in weight of the sealing
member, the end-sealing material, the spacer material and the
colored layer. Also, the total extraction amount of the impurities
denotes the extraction amount in the case where the cell members
were assembled into a liquid crystal cell.
Table 2 shows the experimental data on the display characteristics
covering the case where aniline used as an impurity was added to
the sealing member in various amounts.
TABLE 2 Total extraction amount of Total impurities when Display
characteristics Added Addition impurity extracted with Poor display
Poor display impurity amount content liquid crystal (image
sticking) (poor reliability) aniline 0% 1% 20 ppm none none aniline
2% 4% 70 ppm none none aniline 5% 6% 110 ppm slight image display
unevenness sticking occurred occurred aniline 10% 11% 200 ppm
severe image display unevenness sticking occurred severely
occurred
Table 3 shows the experimental data on the display characteristics
covering the vase where phthalic acid used as an impurity was added
to the sealing member in various amounts.
TABLE 3 Total extraction amount of Total impurities when Display
characteristics Added Addition impurity extracted with Poor display
Poor display impurity amount content liquid crystal (image
sticking) (poor reliability) phthalic acid 0% 1% 20 ppm none none
phthalic acid 2% 4% 80 ppm none none phthalic acid 5% 6% 150 ppm
slightly occurred poor display around filling port occurred around
filling port phthalic acid 10% 11% 320 ppm slightly occurred poor
display around filling severely occurred port around filling
port
Table 4 shows the experimental data on the display characteristics,
covering the case where the spacer of the liquid crystal cell was
prepared by patterning a black resin CK-2000 in place of using the
granular spacer, and benzoic acid used as an impurity was added to
the spacer material in varied amounts.
TABLE 4 Total impurity Total extraction Impurity content of amount
of Addition content colored layer impurities when Display
characteristics Added amount to under under cured extracted with
Poor display Poor display impurity resist resist state state liquid
crystal (image sticking) (poor reliability) benzoic acid 0% 0.05%
1% 40 ppm none none benzoic acid 0.05% 0.10% 2% 90 ppm none none
benzoic acid 0.5% 0.55% 4% 160 ppm none slight occurrence of poor
display benzoic acid 2% 2.05% 11% 250 ppm slight occurrence of
occurrence poor display
Table 5 shows the experimental data on the display characteristics,
covering the case where decanoic acid used as an impurity was added
to the resist for the red colored layer in varied amounts.
TABLE 5 Total impurity Total extraction Impurity content of amount
of Addition content colored layer impurities when Display
characteristics Added amount to under under cured extracted with
Poor display Poor display impurity resist resist state state liquid
crystal (image sticking) (poor reliability) decanoic acid 0% 0.01%
1% 20 ppm none none decanoic acid 0.05% 0.06% 2% 100 ppm none none
decanoic acid 0.5% 0.501% 4% 180 ppm slight occurrence none
decanoic acid 2% 2.01% 11% 260 ppm occurred none
Table 6 shows the experimental data on the display characteristics,
covering the case where used was resist having the impurity content
reduced by using a refined resist for the green colored layer as
well as a refined pigment and a refined dispersant.
TABLE 6 Total extraction amount of Addition Total impurities when
Display characteristics amount to impurity extracted with Poor
display Poor display resist content liquid crystal (image sticking)
(poor reliability) resist for green 0.3% 8% 500 ppm occurred poor
display colored layer not occurred using refining material resist
for green 0.01% 2% 50 ppm none none colored layer using refining
material
FIG. 3 shows a second embodiment of the present invention. In the
first embodiment, the switching element is of reverse staggered
type in which an amorphous silicon is used as a semiconductor
layer. In the second embodiment, however, the switching element is
of a forward staggered type in which a polycrystalline silicon is
used as a semiconductor layer. Also, a columnar spacer is used in
the second embodiment, though a spherical spacer is used in the
first embodiment. In the second embodiment, a black resin having
red, green and blue pigments mixed therein is used for forming the
spacer.
As shown in FIG. 3, a liquid crystal display device 10 of the
second embodiment comprises a counter substrate 120, an array
substrate 310, a liquid crystal layer 70 held between the counter
substrate 120 and the array substrate 310, and a columnar spacer
230 for keeping these two substrates a predetermined distance apart
from each other. The counter substrate 120 includes a glass
substrate 21, a counter electrode 22 formed on the glass substrate
21, and an alignment film 13 formed on the counter electrode 22. On
the other hand, the array substrate 310 includes a glass substrate
210, an undercoating layer 211 of a double-layer structure
consisting of a silicon oxide film and a silicon nitride film and
formed on the glass substrate 210, a semiconductor active layer 214
(channel region) and high impurity regions 213 forming source and
drain regions, said active layer 214 and high impurity regions 213
being formed on the undercoating layer 211, a gate oxide film 212
formed to cover the active layer 214 and the high impurity regions
213, and a gate electrode 215 formed on the gate oxide film 212,
thereby forming a polycrystalline silicon TFT of a forward
staggered type. Incidentally, the scanning line (not shown) is
formed in the step of forming the gate electrode 215. A signal line
219 of a double-layer structure consisting of a Mo layer and an Al
layer is formed on the scanning line and the gate insulating film
212. The signal line 219 is connected to the high impurity regions
213 via a first contact hole 221 extending through an interlayer
insulating film 220 and the gate insulating film 212. An inorganic
insulating film 216 of a double-layer structure consisting of a
silicon oxide film and a silicon nitride film and a colored layer
217 made of an organic resin, having a thickness of 3 .mu.m, and in
the shape of a stripe of red, blue and green colors are formed on
the signal line 219. A second contact hole 222 is formed through
the inorganic insulating film 216 and the colored layer 217. The
columnar spacer 230 is formed on that region of the colored layer
217 in which a pixel electrode is not formed in the subsequent step
to keep the array substrate 310 and the counter substrate 120 a
predetermined distance apart from each other. A pixel electrode 218
consisting of ITO (Indium Tin Oxide) is formed on the colored layer
217 so as to be electrically connected to the signal line 219.
Further, the alignment film 13 is formed to cover the spacer 230,
the pixel electrode 218 and the colored layer 217. The columnar
spacer 230 is formed of a black colored layer, i.e., a layer of
CK-2000 (trade name of an ultraviolet light curing type acrylic
resin consisting of an organic resin and red, green and blue
pigments contained in the organic resin and manufactured by Fuji
Hunt Technology K. K.). In forming the columnar spacer 230, a light
shielding layer was formed simultaneously along the outer periphery
of the substrate.
The amounts of impurities when the colored layer and the spacer are
extracted in the liquid crystal material and the impurity content
of the colored layer and the spacer after formed are defined in the
second embodiment, too, making it possible to obtain a liquid
crystal display device exhibiting good display characteristics.
As described above, the impurities have been found to be contained
in large amounts in, particularly, the green layer among the three
colored layers, supporting that it is effective to define the
impurity content of, particularly, the green layer among the
colored layers. It has also been found that, in the case of using a
black resin, i.e., resin containing red, green and blue pigments,
it is effective to decrease the impurity content of the black resin
because the black resin contains a green pigment.
The particular effect of the present invention can also be obtained
in the case where the technical idea of the present invention is
applied to a liquid crystal display device constructed such that a
color filter is arranged on the counter substrate positioned to
face the array substrate and the counter electrode is formed on the
color filter. In a liquid crystal display device of the particular
construction, a lead-out electrode or the like is patterned in the
step of forming the counter electrode, and the display device
includes a region in which the liquid crystal layer is in contact
with the colored layer directly or with an alignment film
interposed therebetween. It is effective to decrease the impurity
content of the colored layer as in the present invention in the
display device of the particular construction, too. Also, when it
comes to a liquid crystal display device in which an opening is
formed in the counter electrode to partially control the generated
electric field so as to control the direction of alignment of the
liquid crystal molecules, the technical idea of the present
invention produces a prominent effect because the liquid crystal
layer is in contact with the colored layer directly or with the
alignment film interposed therebetween.
As described above, the impurity content of an organic resin film
that is in contact with the liquid crystal layer directly or with a
film that is likely to permit permeation of impurities such as an
alignment film interposed therebetween is decreased in the present
invention so as to obtain a liquid crystal display device capable
of preventing an image sticking and achieving a good display
performance.
It should be noted that the amounts of the impurities contained in
the colored layer, the sealing member and the spacer material are
defined in the present invention so as to prevent nonuniform image
sticking and the display unevenness taking place after the
durability (reliability) test.
Additional advantages and modifications will readily occur to those
skilled in the art. Therefore, the invention in its broader aspects
is not limited to the specific details and representative
embodiments shown and described herein. Accordingly, various
modifications may be made without departing from the spirit or
scope of the general inventive concept as defined by the appended
claims and their equivalents.
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